System independent tissue typing of human testis and prostate

The soft tissues of some organs like testis and prostate can be assumed to be a random distribution of acoustic scatterers. B-mode images of those media appear as homogeneous images with a characteristic texture. In some cases changes of the acoustical parameters due to morphological alterations in the tissue are not or not clearly visible in B-mode images. Based on spectral analysis of RF echo signals and measurements of tissue like phantoms, a procedure was developed to correct for system specific effects and to determine the acoustical attenuation and the relative backscatter coefficient. Both parameters have been shown to be correlated with the tissue state. The method was applied to in vivo measurements of human testis (n=75) and prostate (n=41). Using both parameters the tumor tissue in human testis is detectable with a specificity of 85.4% and a sensitivity of 87.0%. For cancerous prostate tissue the relative backscatter coefficient is 8 dB lower than for normal tissue regions. Imaging the backscatter parameter we can indicate critical regions as a guide for further biopsy.